C# 之委托学习（2）

一个很经典的学习C# 委托的例子跟大家分享一下，希望对大家有点帮助，直接看代码：

BubbleSorter.cs

   
     

    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;


    
      namespace
    
       Wrox.ProCSharp.Delegates
{
 
    
      delegate
    
       
    
      bool
    
       Comparison(
    
      object
    
       x, 
    
      object
    
       y);

 
    
      class
    
       BubbleSorter
 {
 
    
      static
    
       
    
      public
    
       
    
      void
    
       Sort(
    
      object
    
      [] sortArray, Comparison comparer)
 {
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       sortArray.Length; i
    
      ++
    
      )
 {
 
    
      for
    
       (
    
      int
    
       j 
    
      =
    
       i 
    
      +
    
       
    
      1
    
      ; j 
    
      <
    
       sortArray.Length; j
    
      ++
    
      )
 {
 
    
      if
    
       (comparer(sortArray[j], sortArray[i]))
 {
 
    
      object
    
       temp 
    
      =
    
       sortArray[i];
 sortArray[i] 
    
      =
    
       sortArray[j];
 sortArray[j] 
    
      =
    
       temp;
 }
 }
 }
 }
 }
}
   
     

Employee.cs

   
     

    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;


    
      namespace
    
       Wrox.ProCSharp.Delegates
{
 
    
      class
    
       Employee
 {
 
    
      private
    
       
    
      string
    
       name;
 
    
      private
    
       
    
      decimal
    
       salary;

 
    
      public
    
       Employee(
    
      string
    
       name, 
    
      decimal
    
       salary)
 {
 
    
      this
    
      .name 
    
      =
    
       name;
 
    
      this
    
      .salary 
    
      =
    
       salary;
 }

 
    
      public
    
       
    
      override
    
       
    
      string
    
       ToString()
 {
 
    
      return
    
       
    
      string
    
      .Format(
    
      "
    
      {0}, {1:C}
    
      "
    
      , name, salary);
 }

 
    
      public
    
       
    
      static
    
       
    
      bool
    
       CompareSalary(
    
      object
    
       x, 
    
      object
    
       y)
 {
 Employee e1 
    
      =
    
       (Employee)x;
 Employee e2 
    
      =
    
       (Employee)y;
 
    
      return
    
       (e1.salary 
    
      <
    
       e2.salary);
 }
 }

}
   
     

Program.cs

   
     

    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;


    
      namespace
    
       Wrox.ProCSharp.Delegates
{

 
    
      class
    
       Program
 {
 
    
      static
    
       
    
      void
    
       Main()
 {
 Employee[] employees 
    
      =
    
      
 {
 
    
      new
    
       Employee(
    
      "
    
      Bugs Bunny
    
      "
    
      , 
    
      20000
    
      ),
 
    
      new
    
       Employee(
    
      "
    
      Elmer Fudd
    
      "
    
      , 
    
      10000
    
      ),
 
    
      new
    
       Employee(
    
      "
    
      Daffy Duck
    
      "
    
      , 
    
      25000
    
      ),
 
    
      new
    
       Employee(
    
      "
    
      Wiley Coyote
    
      "
    
      , (
    
      decimal
    
      )
    
      1000000.38
    
      ),
 
    
      new
    
       Employee(
    
      "
    
      Foghorn Leghorn
    
      "
    
      , 
    
      23000
    
      ),
 
    
      new
    
       Employee(
    
      "
    
      RoadRunner'
    
      "
    
      , 
    
      50000
    
      )};

 
    
      //
    
       Comparison comp = Employee.CompareSalary; 
    
      //
    
      用Employee.CompareSalary方法实例化一个委托。
    
      

    
      
 BubbleSorter.Sort(employees, Employee.CompareSalary);

 
    
      foreach
    
       (var employee 
    
      in
    
       employees)
 {
 Console.WriteLine(employee);
 }
 Console.ReadLine();
 
    
      //
    
      for (int i = 0; i < employees.Length; i++)
 
    
      //
    
       Console.WriteLine(employees[i].ToString());
    
      

    
       }
 }
}